Resolve "Fetch gameState from server"

backend/src/routes/gameRoutes.ts

frontend/assets/config.properties

...core/src/com/game/tankwars/controller/GameController.java

frontend/core/src/com/game/tankwars/model/CurrentUser.java

frontend/core/src/com/game/tankwars/model/GameState.java

frontend/core/src/com/game/tankwars/model/GameStateTank.java

frontend/core/src/com/game/tankwars/model/Tank.java

frontend/core/src/com/game/tankwars/model/UserTank.java